Multiple dosage injector

Patent metadata

Field	Value
Publication number	US-11058824-B2
Application number	US-201916389336-A
Country	US
Kind code	B2
Filing date	Apr 19, 2019
Priority date	Aug 5, 2008
Publication date	Jul 13, 2021
Grant date	Jul 13, 2021

Abstract

A medicament dispensing mechanism is disclosed that is configured to eject successive doses of the medicament from a medicament chamber. An embodiment of the dispensing mechanism includes a housing and a plunger rod configured for ejecting the doses of medicament from the chamber. The dispensing mechanism further includes an actuation mechanism that comprises a trigger associated with the housing and having a ready and a fired position with respect thereto. The trigger is configured for manipulation by a user for successive movement in a generally axial dosing motion from the ready position to the fired position in which the trigger is associated with the plunger rod to cause the plunger rod to eject one of the doses of a predetermined volume and a resetting motion from the fired position to the ready position that comprises axial rotation, wherein the trigger is uncoupled from the plunger rod during the resetting motion.

First claim

What is claimed is:

1. A medicament dispensing mechanism, comprising:
a housing;
a medicament chamber associated with the housing and configured to contain medicament,
a plunger rod configured to eject successive doses of the medicament from the chamber;
an actuation mechanism that comprises a trigger associated with the housing and having a ready position and a fired position with respect thereto, the trigger being configured for manual engagement by a user for successive movement in:
a dosing motion from the ready position to the fired position generally in axial translation in which the trigger is associated with the plunger rod to cause the plunger rod to eject one of the successive doses of the medicament, and
a resetting motion from the fired position to the ready position, wherein the trigger is uncoupled from the plunger rod during the resetting motion,

an anti-retrograde mechanism associated with the actuation mechanism for preventing rearward movement thereof against the direction of operation of the actuation mechanism through at least a portion of the dosing and resetting motions; and
a lockout mechanism comprising an flexible arm engageable with the trigger to prevent movement of the trigger relative to the after a final dose has been administered.

2. The dispensing mechanism of claim 1 , wherein the trigger comprises a plurality of ready positions and a plurality of fired positions disposed in sequence with each other, and wherein the plurality of ready positions are circumferentially spaced about the housing.

3. The dispensing mechanism of claim 1 , wherein the anti-retrograde mechanism is associated with the trigger for preventing rearward movement thereof from the ready position against the direction of the resetting motion, wherein the anti-retrograde mechanism is associated with the trigger for preventing rearward movement thereof from the fired position against the direction of the dosing motion, and wherein the anti-retrograde mechanism is associated with the trigger for preventing rearward movement thereof from the ready position against the direction of the resetting motion.

4. The dispensing mechanism of claim 3 , wherein:
one of the trigger and housing includes a projection; and
the other of the trigger and housing includes a track for receiving the projection and defining the dosing and resetting motions, wherein the track has a first tab disposed therein with a free end configured for engaging the projection and preventing rearward movement thereof from the fired position against the direction of the dosing motion, and wherein the track has a second tab disposed therein with a free end configured for engaging the projection and for preventing rearward movement thereof from the ready position against the direction of the resetting motion.

5. The dispensing mechanism of claim 1 , wherein the actuation mechanism comprises a driver rotatably associated with the housing and driven to rotate in a driving direction by the trigger during the dosing motion.

6. The dispensing mechanism of claim 5 , wherein the driving direction is in an opposite rotational direction than the rotational spacing between the fired position and adjacent ready position of the trigger, the driver being associated with the plunger rod for causing the plunger rod to eject said one of the doses.

7. The dispensing mechanism of claim 5 , wherein:
one of the housing and trigger includes a first projection, and the other of the trigger and driver includes a first track, wherein the first track is configured for receiving the first projection and defining the dosing and resetting motions of the trigger with respect to the housing; and
one of the trigger and driver includes a second projection, and the other of the trigger and driver includes a second track, wherein the second track is configured for receiving the second projection, applying a force to the second projection during the dosing motion of the trigger to rotate the driver in the driving direction, and allow the resetting motion of the trigger without rotating the driver.

8. The dispensing mechanism of claim 7 , wherein the housing defines the first track and the trigger defines the first projection, and wherein the trigger defines the second track and the driver defines the second projection, wherein the first track defines a succession of a plurality of the ready positions interposed in continuous series by a plurality of the fired positions and paths for the corresponding dosing and resetting motions therebetween, and
wherein the second track comprises a plurality of driving portions for causing the trigger to rotate the driver in each of the dosing motions connected in continuous series by alternately applying a force to the second projection during successive dosing motions of the trigger to rotate the driver in the driving direction.

9. The dispensing mechanism of claim 7 , wherein the second track has a resetting portion aligned substantially axially to allow the resetting motion of the trigger without rotating the driver.

10. The dispensing mechanism of claim 5 , wherein the driving direction is opposite from the direction of rotation of the trigger in the resetting motion.

11. The dispensing mechanism of claim 1 , wherein:
the actuation mechanism comprises a driver rotatably associated with the housing and driven to rotate by the trigger during the dosing motion;
the driver is associated with the plunger rod for causing the plunger rod to eject said one of the doses;
the anti-retrograde mechanism is configured for preventing rearward movement of the driver with respect to the trigger against the dosing motion;
one of the trigger and driver includes a projection; and
the other of the trigger and driver includes stepped surfaces facing a relative path of the projection during the dosing motion, the stepped surfaces configured for engaging the projection during rearward movement therebetween for preventing rearward movement of the trigger.

12. The dispensing mechanism of claim 11 , wherein the stepped surfaces are substantially flat and face axially, and wherein the projection defines a notch to receive an edge of the stepped surfaces.

13. The dispensing mechanism of claim 11 , wherein said other one of the trigger and driver comprising a sloped surface opposite the stepped surfaces and engaged with the projection during the dosing motion to cause the trigger to cam the driver for rotating and driving the plunger rod.

14. The dispensing mechanism of claim 11 , wherein the anti-retrograde mechanism is configured for preventing rearward movement of the driver with respect to the housing.

15. The dispensing mechanism of claim 11 , wherein the anti-retrograde mechanism is configured for preventing rearward movement of the plunger rod.

16. The dispensing mechanism of claim 15 , wherein the lock is configured for preventing the rearward movement of the plunger rod only after a predetermined number of doses have been ejected from the chamber and disabling the actuation mechanism by including a flexible arm disposed within the housing, the plunger rod being configured to force a portion of the flexible arm axially outwardly after the predetermined number of doses have been ejected from the chamber, and the flexible arm being configured to engage a portion of the trigger to prevent further motion of the trigger in the resetting motion to disable the actuation mechanism.

17. The medicament dispensing mechanism of claim 1 , wherein the flexible arm is disposed within the housing, the plunger rod being configured to force a

Assignees

• Antares Pharma Inc

Inventors

• Cox Janice L
• Rust Matthew H
• Kramer Thomas E
• Hoeft Peter A

Classifications

• A61M5/24

  Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic {(ampoules or carpules A61J1/06)} · CPC title

• A61M5/31541

  Means preventing setting of a dose beyond the amount remaining in the cartridge · CPC title

• A61M5/31566

  Means improving security or handling thereof · CPC title

• A61M5/3158

  performed by axially moving actuator operated by user, e.g. an injection button · CPC title

• A61M2005/2407

  from the rear · CPC title